Optimum synthesis of CuO nanoparticles with the highest antifungal activity against oral pathogen Candida albicans

This research was aimed to optimize the synthesis of copper oxide (CuO) nanoparticles with the highest antifungalproperties against Candida albicans as an oral fungal pathogen. To this end, nine experiments involving differentsynthesis conditions were designed using the Taguchi method and the copper oxide nanoparticles synthesized bycoprecipitation method. The antifungal activity of synthesized nanoparticles against C. albicans was evaluatedusing the colony forming unit and disk diffusion methods. According to the results, the synthesized copper oxidenanoparticles under the five experimental conditions (CuCl2 0.1 M, NaOH 0.1 M, and a 75 minutes stirring time)showed the highest antifungal activity against C. albicans (71.72%). The optimization results demonstrated thatall three studied factors were effective in improving the antifungal activity of copper oxide nanoparticles and theantifungal activity in the proposed conditions can be improved by 77.85%. The synthesis of nanoparticles in optimalconditions confirmed the improved antifungal activity of the nanoparticles. The results of this study proved that CuOnanoparticles have a potential ability as an antifungal agent against oral fungal pathogens of C. albicans.

Nanopartículas de CuO y su propiedad antimicrobiana en cepas intrahospitalarias / CuO nanoparticles and their antimicrobial activity against nosocomial strains / Nanopartículas de CuO e sua propriedade antimicrobiana frente a cepas intrahospitalares

Resumen Empleando un prototipo de reactor, se sintetizaron nanopartículas (NPs) de CuO a través del método de precipitación a partir de CuSO25H2O y de Cu(CH3COO)2H2O. Las NPs obtenidas fueron caracterizadas mediante XRD, FT-IR, TEM y SEM. La actividad antimicrobiana de las NPs se determinó mediante el método de difusión en placa, colocando 20 mg de NPs de CuO sobre cuatro cepas intrahospitalarias o nosocomiales aisladas de la Unidad de Cuidados Intensivos de un hospital nacional de Lima norte (Staphylococcus epidermidis, Aerococcus viridans, Ochrobactrum anthropi y Micrococcus lylae). La caracterización de las NPs de CuO demostró que las sintetizadas a partir de acetato (CuO-Acet) presentaron una fase pura de CuO, mientras que las sintetizadas a partir de sulfato (CuO-Sulf) presentaron dos fases, donde la de CuO representó más del 84%. Los dominios cristalinos del CuO-Acet y CuO-Sulf fueron 15 y 19 nm, respectivamente. Los halos de inhibición de las cepas estudiadas fueron mayores para las NPs de CuO-Sulf que para las NPs de CuO-Acet; solo para la cepa Ochrobactrum anthropi se presentaron halos similares para ambos tipos de NPs.

Abstract Using a prototype reactor, CuO nanoparticles (NPs) were synthetized through the precipitation method, starting from CuSO2 5H2O and Cu(CH3COO)2H2O. The obtained NPs were characterized by XDR, FT-IR, SEM, and TEM. The antimicrobial activity of the NPs was determined by the plate diffusion method, placing 20 mg of NPs onto four nosocomial strains obtained from north Lima national hospital Intensive-Care Unit (Staphylococcus epidermidis, Aerococcus viridans, Ochrobactrum anthropic, and Micrococcus lylae). NPs characterization revealed that those synthetized from acetate (CuO-Acet) shown pure CuO phase, while those synthetized from sulphate CuO-Sulf shown two phases where CuO was the predominant one, having more than 84%. The crystal domains for CuO-Acet and CuO-Sulf were 15 and 19 nm, respectively. The inhibition halos for the studied strains were larger for CuO-Sulf NPs than CuO-Acet NPs, only Ochrobactrum anthropi displayed similar inhibition halos for both types of NPs.

Resumo Usando um protótipo de reator, sintetizaram-se nanopartículas (NPs) de CuO pelo método de precipitação a partir de CuSO25H2O e de Cu(CH3COO)2H2O. As NPs obtidas foram caracterizadas por meio das seguintes técnicas: XRD, FT-IR, TEM e SEM. A atividade antimicrobiana das NPs foi determinada pelo método de difusão em placa, colocando 20 mg de NPs de CuO sobre quatro cepas nosocomiais isoladas de uma Unidade de Terapia Intensiva no hospital nacional de Lima norte (Staphylococcus epidermidis, Aerococcus viridans, Ochrobactrum anthropic e Micrococcus lylae). A caracterização das NPs de CuO mostrou que as nanopartículas sintetizadas a partir do acetato (CuO-Acet) apresentavam uma fase pura de CuO, enquanto que as sintetizadas a partir do sulfato (CuO-Sulf), apresentaram duas fases sendo a fase maior de CuO, com mais de 84%. Os domínios cristalinos de CuO-Acet y CuO-Sulf foram 15 e 19 nm, respectivamente. Os halos de inibição das cepas estudadas foram maiores para as NPs de CuO-Sulf do que as NPs de CuO-Acet somente para a cepa Ochrobactrum anthropi, apresentaram-se halos de inibição parecidos.